I've had mine for a month. Currently it is my favorite reader although I don't like not having and microSD card

- good size
- good screen
- decent battery
- full access (Android), use the ebook software you want (fbreader)
- Speaker is pretty good (not up to Xoom or nokia n800)
- use ES explorer software to manage my books

for me at $200 is hit the sweet spot of good enough

I like the Nexus 7 as well.
Before, BlackBerry PlayBook was one of my favorite tablets for reading. iPad and the likes I find way too heavy for extended reading sessions >2 or 3 hours.
Nexus 7 even is a bit lighter than PlayBook. And of course there are way more apps on Android than on BlackBerry. (I've transferred a few Android apps to PlayBook and it works good enough, but I don't like the hassle).
Some reviews state, the display of Nexus 7 isn't that good. Honestly, I haven't really compared yet. It may be less vibrant than iPad's or PlayBook's display, but it certainly is good enough for reading and browsing the web.
The battery could have a higher capacity, I have to charge every single day.
Still: For this price, it's absolutely phantastic.
And of course Jellybean 4.1.1 with "Google Now" is another step forward. And as long as iOS doesn't offer alternative keyboards (such as Swype for example), I prefer Android tablets over my iPad 3 anytime...